The disclosed embodiments of the present invention relate to power management, and more particularly, to a power management method for controlling a communication interface to enter/leave a power-saving mode and related device thereof.
Generally, a host transmits data to and receives data from a device through a communication interface. To reduce the power consumption, a power management may be employed to manage the operation of the communication interface. One conventional power management design is to make the communication interface operated under a power-saving mode during a period starting from the end of a previous command issued from the host to the device and ending at the beginning of the current command issued from the host to the device. In other words, this conventional power management design only enables the power-saving sequence during a command gap between two successive commands generated from the host to the device. The length of the command gap between two successive commands depends on host's execution efficiency. However, regarding a low-speed device, performing the power-saving sequence during the command gap between two successive commands cannot save much power due to the fact that communication interface may spend much time on waiting for the end of the command processed by the low-speed device.
Besides, in accordance with the conventional power management design, the communication interface enters the power-saving mode when the previous command is finished and leaves the power-saving mode when the current command is sent from the host. As the communication interface needs some time to wake up from the power-saving mode, the device therefore is unable to receive and process the host command immediately. As a result, the data transmission efficiency may be degraded.